docs: def check_exists_in_dictionary(method, dictionary, required_fields, label=None):
      """Checks if required fields have a value in the object instance.
      Throws an exception with the missing fields.
  
      :param dict dictionary: Dictionary to check.
      :param typle required_fields: Required fields that must have a value.
      :param string label: Dictionary name.
      """
      missing = []
      for field in required_fields:
          if field not in dictionary or dictionary[field] is None:
              missing.append(field)
      if missing:
          error_label = ' for "%s"' % label if label else ''
          raise PyCronofyValidationError('Method: %s. Missing required field(s)%s: %s' % (method, error_label, missing),
                                         method,
                                         missing
                                         )